Monday, March 23, 2015

Chemical method (non-protein) blocking of protein microarrays

We're working to
continually improve protein microarray performance. Recently we have
developed a chemical blocking procedure to increase signal to noise ratio and
eliminate any potential noise caused by the most difficult body fluids, such as
whole blood, cellular and tissue lysates, urine, perspiration, tears,
feces, to name a few. Data for easier samples such as serum and plasma
is improved. In some immunoassay type microarrays, a patient
could be making antibodies to the proteins used to block the slide surface
chemistry, resulting in very high background. An example of this is using a traditional powdered milk blocking buffer and reacting a patient blood sample who is allergic to milk proteins. Chemical blocking buffers remove this possibility and any
potential of protein blocking buffers to interact with the epitopes of proteins printed on
the microarray. The picture below is the same sample and microarray,
two different results. Notice how the microarray on the right shows
detectable signal whereas on the left, the signal from spots is lost in the
background showing what is called "black holes" for many of the data points.